/*
 * $Id$
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.struts2.osgi.virgo;

import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;

import com.opensymphony.xwork2.FileManager;
import com.opensymphony.xwork2.ObjectFactory;
import com.opensymphony.xwork2.config.Configuration;
import com.opensymphony.xwork2.config.ConfigurationException;
import com.opensymphony.xwork2.config.entities.PackageConfig;
import com.opensymphony.xwork2.config.impl.DefaultConfiguration;
import com.opensymphony.xwork2.config.providers.XmlConfigurationProvider;

/**
 * Package loader implementation that loads resources from a bundle
 */
public class BundlePackageLoader implements PackageLoader {
//	private static final Logger LOG = LoggerFactory.getLogger(BundlePackageLoader.class);

	@Override
	public List<PackageConfig> loadPackages(Bundle bundle, BundleContext bundleContext, ObjectFactory objectFactory,
			FileManager fileManager, Map<String, PackageConfig> pkgConfigs) throws ConfigurationException {
		Configuration config = new DefaultConfiguration("struts.xml");
		BundleConfigurationProvider prov = new BundleConfigurationProvider("struts.xml", bundle, bundleContext);
		for (PackageConfig pkg : pkgConfigs.values()) {
			config.addPackageConfig(pkg.getName(), pkg);
		}
		prov.setFileManager(fileManager);
		prov.setObjectFactory(objectFactory);
		prov.init(config);
		prov.loadPackages();

		List<PackageConfig> list = new ArrayList<PackageConfig>(config.getPackageConfigs().values());
		list.removeAll(pkgConfigs.values());

		return list;
	}

	static class BundleConfigurationProvider extends XmlConfigurationProvider {
		private Bundle bundle;

		public BundleConfigurationProvider(String filename, Bundle bundle, BundleContext bundleContext) {
			super(filename, false);
			this.bundle = bundle;
		}

		public BundleConfigurationProvider(String filename) {
			super(filename);
		}

		@Override
		protected Iterator<URL> getConfigurationUrls(String fileName) throws IOException {
			Enumeration<URL> e = bundle.getResources("struts.xml");
			return e.hasMoreElements() ? new EnumeratorIterator<URL>(e) : null;
		}
	}

	static class EnumeratorIterator<E> implements Iterator<E> {
		Enumeration<E> e = null;

		public EnumeratorIterator(Enumeration<E> e) {
			this.e = e;
		}

		public boolean hasNext() {
			return e.hasMoreElements();
		}

		public E next() {
			return e.nextElement();
		}

		public void remove() {
			throw new UnsupportedOperationException();
		}
	}
}
